In modern "enterprise" digital data processing systems, that is, computer systems for use in an office environment in a company, a number of personal computers, workstations, and other devices such as mass storage subsystems, network printers and interfaces to the public telephony system, are typically interconnected in a computer network. The personal computers and workstations are used by individual workers to perform processing in connection with data and programs that may be stored in the network mass storage subsystems; the personal computers/workstations, operating as clients, download the data and programs from the network mass storage subsystems process the data in connection with the programs and enable the processed data to be uploaded to the network mass storage subsystems for storage, to a network printer for printing, or to the telephony interface for transmission over the public telephony system. In such an arrangement, the network mass storage subsystems, network printers and telephony interface operate as servers, since they are available to service requests from all of the clients in the network. By organizing the network in such a manner, the servers are readily available for use by all of the personal computers/workstations in the network. Such a network may be spread over a fairly wide area, with the personal computers/workstations are interconnected by communication links such as electrical wires or optic fibers.
Sometimes during processing, a personal computer/workstation, or any device controlled by a program, may become "hung," that is, because of errors in a program or certain undesirable combinations of data being processed, it may become stuck in an endless program loop. In such a condition, the device is essentially stopped. Particularly if the device is a server, if the device becomes hung it may not be able to service requests from any of the clients, which can cause significant problems for the clients' ability to perform their respective processing tasks.